Glass Tower That Might Actually be Energy Efficient

The recently completed Beijing Greenland Center, built by Chicago’s Skidmore, Owings & Merrill (SOM) may not look like a very energy efficient building at first glance, given it’s glazed façade. However, the trapezoidal shape of the windows is said to actually improve the building’s energy performance. The Beijing Greenland Center is 853 ft (260 m) high and has 55 floors. It’s located in the city’s Dawangjing business district and contains offices and 178 of apartments. There is also a multi-story retail zone attached to it.

Bas-relief sculpting technique served as the inspiration for the interesting pattern of the glazed façade, which is made of two types of trapezoidal Low-E (efficient) glass modules. One of these types is tapered upward, and the other downward, and this pattern alternates across the facade and thereby refracts the sunlight inside and out. Since Beijing is a rather cloudy city, these interestingly placed windows are meant to let plenty of daylight into the building, while also reflecting some of it back onto the city.

According to SOM, the trapezoid shape of the glazed façade also improves the tower’s thermal performance, primarily by cutting down on solar heat gain, which would be a lot greater if the façade was completely flat. SOM is also confident that the building will prove to have a 30 percent reduction in energy use and water consumption in comparison to a baseline building, which probably refers to other towers in China.

The tower is also equipped with other energy-efficient technologies, such as variable speed pumps for heating and cooling, an evaporative cooling system, and an energy recovery heat exchange system which recaptures exhaust gases and hot air and reuses them for heating (thermal wheel).

There is also a park attached to the building, as well as several walkways and bicycle lanes to facilitate car-less travel to work. The SOM San Francisco office is also building three more towers in the nearby area.